# Lo-Dash v2.4.2
## `Arrays`
* `_.compact`
* `_.difference`
* `_.drop` -> `rest`
* `_.findIndex`
* `_.findLastIndex`
* `_.first`
* `_.flatten`
* `_.head` -> `first`
* `_.indexOf`
* `_.initial`
* `_.intersection`
* `_.last`
* `_.lastIndexOf`
* `_.object` -> `zipObject`
* `_.pull`
* `_.range`
* `_.remove`
* `_.rest`
* `_.sortedIndex`
* `_.tail` -> `rest`
* `_.take` -> `first`
* `_.union`
* `_.uniq`
* `_.unique` -> `uniq`
* `_.unzip` -> `zip`
* `_.without`
* `_.xor`
* `_.zip`
* `_.zipObject`
## `Chaining`
* `_`
* `_.chain`
* `_.tap`
* `_.prototype.chain`
* `_.prototype.toString`
* `_.prototype.value` -> `valueOf`
* `_.prototype.valueOf`
## `Collections`
* `_.all` -> `every`
* `_.any` -> `some`
* `_.at`
* `_.collect` -> `map`
* `_.contains`
* `_.countBy`
* `_.detect` -> `find`
* `_.each` -> `forEach`
* `_.eachRight` -> `forEachRight`
* `_.every`
* `_.filter`
* `_.find`
* `_.findLast`
* `_.findWhere` -> `find`
* `_.foldl` -> `reduce`
* `_.foldr` -> `reduceRight`
* `_.forEach`
* `_.forEachRight`
* `_.groupBy`
* `_.include` -> `contains`
* `_.indexBy`
* `_.inject` -> `reduce`
* `_.invoke`
* `_.map`
* `_.max`
* `_.min`
* `_.pluck`
* `_.reduce`
* `_.reduceRight`
* `_.reject`
* `_.sample`
* `_.select` -> `filter`
* `_.shuffle`
* `_.size`
* `_.some`
* `_.sortBy`
* `_.toArray`
* `_.where`
## `Functions`
* `_.after`
* `_.bind`
* `_.bindAll`
* `_.bindKey`
* `_.compose`
* `_.curry`
* `_.debounce`
* `_.defer`
* `_.delay`
* `_.memoize`
* `_.once`
* `_.partial`
* `_.partialRight`
* `_.throttle`
* `_.wrap`
## `Objects`
* `_.assign`
* `_.clone`
* `_.cloneDeep`
* `_.create`
* `_.defaults`
* `_.extend` -> `assign`
* `_.findKey`
* `_.findLastKey`
* `_.forIn`
* `_.forInRight`
* `_.forOwn`
* `_.forOwnRight`
* `_.functions`
* `_.has`
* `_.invert`
* `_.isArguments`
* `_.isArray`
* `_.isBoolean`
* `_.isDate`
* `_.isElement`
* `_.isEmpty`
* `_.isEqual`
* `_.isFinite`
* `_.isFunction`
* `_.isNaN`
* `_.isNull`
* `_.isNumber`
* `_.isObject`
* `_.isPlainObject`
* `_.isRegExp`
* `_.isString`
* `_.isUndefined`
* `_.keys`
* `_.mapValues`
* `_.merge`
* `_.methods` -> `functions`
* `_.omit`
* `_.pairs`
* `_.pick`
* `_.transform`
* `_.values`
## `Utilities`
* `_.constant`
* `_.createCallback`
* `_.escape`
* `_.identity`
* `_.mixin`
* `_.noConflict`
* `_.noop`
* `_.now`
* `_.parseInt`
* `_.property`
* `_.random`
* `_.result`
* `_.runInContext`
* `_.template`
* `_.times`
* `_.unescape`
* `_.uniqueId`
## `Methods`
* `_.templateSettings.imports._`
## `Properties`
* `_.VERSION`
* `_.support`
* `_.support.argsClass`
* `_.support.argsObject`
* `_.support.enumErrorProps`
* `_.support.enumPrototypes`
* `_.support.funcDecomp`
* `_.support.funcNames`
* `_.support.nonEnumArgs`
* `_.support.nonEnumShadows`
* `_.support.ownLast`
* `_.support.spliceObjects`
* `_.support.unindexedChars`
* `_.templateSettings`
* `_.templateSettings.escape`
* `_.templateSettings.evaluate`
* `_.templateSettings.imports`
* `_.templateSettings.interpolate`
* `_.templateSettings.variable`
## `“Arrays” Methods`
### `_.compact(array)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4480 "View in source") [Ⓣ][1]
Creates an array with all falsey values removed. The values `false`, `null`,
`0`, `""`, `undefined`, and `NaN` are all falsey.
#### Arguments
1. `array` *(Array)*: The array to compact.
#### Returns
*(Array)*: Returns a new array of filtered values.
#### Example
```js
_.compact([0, 1, false, 2, '', 3]);
// => [1, 2, 3]
```
* * *
### `_.difference(array, [values])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4509 "View in source") [Ⓣ][1]
Creates an array excluding all values of the provided arrays using strict
equality for comparisons, i.e. `===`.
#### Arguments
1. `array` *(Array)*: The array to process.
2. `[values]` *(...Array)*: The arrays of values to exclude.
#### Returns
*(Array)*: Returns a new array of filtered values.
#### Example
```js
_.difference([1, 2, 3, 4, 5], [5, 2, 10]);
// => [1, 3, 4]
```
* * *
### `_.findIndex(array, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4554 "View in source") [Ⓣ][1]
This method is like `_.find` except that it returns the index of the first
element that passes the callback check, instead of the element itself.
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `array` *(Array)*: The array to search.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(number)*: Returns the index of the found element, else `-1`.
#### Example
```js
var characters = [
{ 'name': 'barney', 'age': 36, 'blocked': false },
{ 'name': 'fred', 'age': 40, 'blocked': true },
{ 'name': 'pebbles', 'age': 1, 'blocked': false }
];
_.findIndex(characters, function(chr) {
return chr.age < 20;
});
// => 2
// using "_.where" callback shorthand
_.findIndex(characters, { 'age': 36 });
// => 0
// using "_.pluck" callback shorthand
_.findIndex(characters, 'blocked');
// => 1
```
* * *
### `_.findLastIndex(array, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4608 "View in source") [Ⓣ][1]
This method is like `_.findIndex` except that it iterates over elements
of a `collection` from right to left.
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `array` *(Array)*: The array to search.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(number)*: Returns the index of the found element, else `-1`.
#### Example
```js
var characters = [
{ 'name': 'barney', 'age': 36, 'blocked': true },
{ 'name': 'fred', 'age': 40, 'blocked': false },
{ 'name': 'pebbles', 'age': 1, 'blocked': true }
];
_.findLastIndex(characters, function(chr) {
return chr.age > 30;
});
// => 1
// using "_.where" callback shorthand
_.findLastIndex(characters, { 'age': 36 });
// => 0
// using "_.pluck" callback shorthand
_.findLastIndex(characters, 'blocked');
// => 2
```
* * *
### `_.first(array, [callback], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4670 "View in source") [Ⓣ][1]
Gets the first element or first `n` elements of an array. If a callback
is provided elements at the beginning of the array are returned as long
as the callback returns truey. The callback is bound to `thisArg` and
invoked with three arguments; (value, index, array).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Aliases
*_.head, _.take*
#### Arguments
1. `array` *(Array)*: The array to query.
2. `[callback]` *(Function|Object|number|string)*: The function called per element or the number of elements to return. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(*)*: Returns the first element(s) of `array`.
#### Example
```js
_.first([1, 2, 3]);
// => 1
_.first([1, 2, 3], 2);
// => [1, 2]
_.first([1, 2, 3], function(num) {
return num < 3;
});
// => [1, 2]
var characters = [
{ 'name': 'barney', 'blocked': true, 'employer': 'slate' },
{ 'name': 'fred', 'blocked': false, 'employer': 'slate' },
{ 'name': 'pebbles', 'blocked': true, 'employer': 'na' }
];
// using "_.pluck" callback shorthand
_.first(characters, 'blocked');
// => [{ 'name': 'barney', 'blocked': true, 'employer': 'slate' }]
// using "_.where" callback shorthand
_.pluck(_.first(characters, { 'employer': 'slate' }), 'name');
// => ['barney', 'fred']
```
* * *
### `_.flatten(array, [isShallow=false], [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4730 "View in source") [Ⓣ][1]
Flattens a nested array (the nesting can be to any depth). If `isShallow`
is truey, the array will only be flattened a single level. If a callback
is provided each element of the array is passed through the callback before
flattening. The callback is bound to `thisArg` and invoked with three
arguments; (value, index, array).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `array` *(Array)*: The array to flatten.
2. `[isShallow=false]` *(boolean)*: A flag to restrict flattening to a single level.
3. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
4. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Array)*: Returns a new flattened array.
#### Example
```js
_.flatten([1, [2], [3, [[4]]]]);
// => [1, 2, 3, 4];
_.flatten([1, [2], [3, [[4]]]], true);
// => [1, 2, 3, [[4]]];
var characters = [
{ 'name': 'barney', 'age': 30, 'pets': ['hoppy'] },
{ 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] }
];
// using "_.pluck" callback shorthand
_.flatten(characters, 'pets');
// => ['hoppy', 'baby puss', 'dino']
```
* * *
### `_.indexOf(array, value, [fromIndex=0])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4767 "View in source") [Ⓣ][1]
Gets the index at which the first occurrence of `value` is found using
strict equality for comparisons, i.e. `===`. If the array is already sorted
providing `true` for `fromIndex` will run a faster binary search.
#### Arguments
1. `array` *(Array)*: The array to search.
2. `value` *(*)*: The value to search for.
3. `[fromIndex=0]` *(boolean|number)*: The index to search from or `true` to perform a binary search on a sorted array.
#### Returns
*(number)*: Returns the index of the matched value or `-1`.
#### Example
```js
_.indexOf([1, 2, 3, 1, 2, 3], 2);
// => 1
_.indexOf([1, 2, 3, 1, 2, 3], 2, 3);
// => 4
_.indexOf([1, 1, 2, 2, 3, 3], 2, true);
// => 2
```
* * *
### `_.initial(array, [callback=1], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4828 "View in source") [Ⓣ][1]
Gets all but the last element or last `n` elements of an array. If a
callback is provided elements at the end of the array are excluded from
the result as long as the callback returns truey. The callback is bound
to `thisArg` and invoked with three arguments; (value, index, array).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `array` *(Array)*: The array to query.
2. `[callback=1]` *(Function|Object|number|string)*: The function called per element or the number of elements to exclude. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Array)*: Returns a slice of `array`.
#### Example
```js
_.initial([1, 2, 3]);
// => [1, 2]
_.initial([1, 2, 3], 2);
// => [1]
_.initial([1, 2, 3], function(num) {
return num > 1;
});
// => [1]
var characters = [
{ 'name': 'barney', 'blocked': false, 'employer': 'slate' },
{ 'name': 'fred', 'blocked': true, 'employer': 'slate' },
{ 'name': 'pebbles', 'blocked': true, 'employer': 'na' }
];
// using "_.pluck" callback shorthand
_.initial(characters, 'blocked');
// => [{ 'name': 'barney', 'blocked': false, 'employer': 'slate' }]
// using "_.where" callback shorthand
_.pluck(_.initial(characters, { 'employer': 'na' }), 'name');
// => ['barney', 'fred']
```
* * *
### `_.intersection([array])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4858 "View in source") [Ⓣ][1]
Creates an array of unique values present in all provided arrays using
strict equality for comparisons, i.e. `===`.
#### Arguments
1. `[array]` *(...Array)*: The arrays to inspect.
#### Returns
*(Array)*: Returns an array of shared values.
#### Example
```js
_.intersection([1, 2, 3], [5, 2, 1, 4], [2, 1]);
// => [1, 2]
```
* * *
### `_.last(array, [callback], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4958 "View in source") [Ⓣ][1]
Gets the last element or last `n` elements of an array. If a callback is
provided elements at the end of the array are returned as long as the
callback returns truey. The callback is bound to `thisArg` and invoked
with three arguments; (value, index, array).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `array` *(Array)*: The array to query.
2. `[callback]` *(Function|Object|number|string)*: The function called per element or the number of elements to return. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(*)*: Returns the last element(s) of `array`.
#### Example
```js
_.last([1, 2, 3]);
// => 3
_.last([1, 2, 3], 2);
// => [2, 3]
_.last([1, 2, 3], function(num) {
return num > 1;
});
// => [2, 3]
var characters = [
{ 'name': 'barney', 'blocked': false, 'employer': 'slate' },
{ 'name': 'fred', 'blocked': true, 'employer': 'slate' },
{ 'name': 'pebbles', 'blocked': true, 'employer': 'na' }
];
// using "_.pluck" callback shorthand
_.pluck(_.last(characters, 'blocked'), 'name');
// => ['fred', 'pebbles']
// using "_.where" callback shorthand
_.last(characters, { 'employer': 'na' });
// => [{ 'name': 'pebbles', 'blocked': true, 'employer': 'na' }]
```
* * *
### `_.lastIndexOf(array, value, [fromIndex=array.length-1])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5004 "View in source") [Ⓣ][1]
Gets the index at which the last occurrence of `value` is found using strict
equality for comparisons, i.e. `===`. If `fromIndex` is negative, it is used
as the offset from the end of the collection.
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `array` *(Array)*: The array to search.
2. `value` *(*)*: The value to search for.
3. `[fromIndex=array.length-1]` *(number)*: The index to search from.
#### Returns
*(number)*: Returns the index of the matched value or `-1`.
#### Example
```js
_.lastIndexOf([1, 2, 3, 1, 2, 3], 2);
// => 4
_.lastIndexOf([1, 2, 3, 1, 2, 3], 2, 3);
// => 1
```
* * *
### `_.pull(array, [value])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5034 "View in source") [Ⓣ][1]
Removes all provided values from the given array using strict equality for
comparisons, i.e. `===`.
#### Arguments
1. `array` *(Array)*: The array to modify.
2. `[value]` *(...*)*: The values to remove.
#### Returns
*(Array)*: Returns `array`.
#### Example
```js
var array = [1, 2, 3, 1, 2, 3];
_.pull(array, 2, 3);
console.log(array);
// => [1, 1]
```
* * *
### `_.range([start=0], end, [step=1])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5085 "View in source") [Ⓣ][1]
Creates an array of numbers (positive and/or negative) progressing from
`start` up to but not including `end`. If `start` is less than `stop` a
zero-length range is created unless a negative `step` is specified.
#### Arguments
1. `[start=0]` *(number)*: The start of the range.
2. `end` *(number)*: The end of the range.
3. `[step=1]` *(number)*: The value to increment or decrement by.
#### Returns
*(Array)*: Returns a new range array.
#### Example
```js
_.range(4);
// => [0, 1, 2, 3]
_.range(1, 5);
// => [1, 2, 3, 4]
_.range(0, 20, 5);
// => [0, 5, 10, 15]
_.range(0, -4, -1);
// => [0, -1, -2, -3]
_.range(1, 4, 0);
// => [1, 1, 1]
_.range(0);
// => []
```
* * *
### `_.remove(array, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5138 "View in source") [Ⓣ][1]
Removes all elements from an array that the callback returns truey for
and returns an array of removed elements. The callback is bound to `thisArg`
and invoked with three arguments; (value, index, array).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `array` *(Array)*: The array to modify.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Array)*: Returns a new array of removed elements.
#### Example
```js
var array = [1, 2, 3, 4, 5, 6];
var evens = _.remove(array, function(num) { return num % 2 == 0; });
console.log(array);
// => [1, 3, 5]
console.log(evens);
// => [2, 4, 6]
```
* * *
### `_.rest(array, [callback=1], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5207 "View in source") [Ⓣ][1]
The opposite of `_.initial` this method gets all but the first element or
first `n` elements of an array. If a callback function is provided elements
at the beginning of the array are excluded from the result as long as the
callback returns truey. The callback is bound to `thisArg` and invoked
with three arguments; (value, index, array).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Aliases
*_.drop, _.tail*
#### Arguments
1. `array` *(Array)*: The array to query.
2. `[callback=1]` *(Function|Object|number|string)*: The function called per element or the number of elements to exclude. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Array)*: Returns a slice of `array`.
#### Example
```js
_.rest([1, 2, 3]);
// => [2, 3]
_.rest([1, 2, 3], 2);
// => [3]
_.rest([1, 2, 3], function(num) {
return num < 3;
});
// => [3]
var characters = [
{ 'name': 'barney', 'blocked': true, 'employer': 'slate' },
{ 'name': 'fred', 'blocked': false, 'employer': 'slate' },
{ 'name': 'pebbles', 'blocked': true, 'employer': 'na' }
];
// using "_.pluck" callback shorthand
_.pluck(_.rest(characters, 'blocked'), 'name');
// => ['fred', 'pebbles']
// using "_.where" callback shorthand
_.rest(characters, { 'employer': 'slate' });
// => [{ 'name': 'pebbles', 'blocked': true, 'employer': 'na' }]
```
* * *
### `_.sortedIndex(array, value, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5271 "View in source") [Ⓣ][1]
Uses a binary search to determine the smallest index at which a value
should be inserted into a given sorted array in order to maintain the sort
order of the array. If a callback is provided it will be executed for
`value` and each element of `array` to compute their sort ranking. The
callback is bound to `thisArg` and invoked with one argument; (value).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `array` *(Array)*: The array to inspect.
2. `value` *(*)*: The value to evaluate.
3. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
4. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(number)*: Returns the index at which `value` should be inserted
into `array`.
#### Example
```js
_.sortedIndex([20, 30, 50], 40);
// => 2
// using "_.pluck" callback shorthand
_.sortedIndex([{ 'x': 20 }, { 'x': 30 }, { 'x': 50 }], { 'x': 40 }, 'x');
// => 2
var dict = {
'wordToNumber': { 'twenty': 20, 'thirty': 30, 'fourty': 40, 'fifty': 50 }
};
_.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
return dict.wordToNumber[word];
});
// => 2
_.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
return this.wordToNumber[word];
}, dict);
// => 2
```
* * *
### `_.union([array])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5302 "View in source") [Ⓣ][1]
Creates an array of unique values, in order, of the provided arrays using
strict equality for comparisons, i.e. `===`.
#### Arguments
1. `[array]` *(...Array)*: The arrays to inspect.
#### Returns
*(Array)*: Returns an array of combined values.
#### Example
```js
_.union([1, 2, 3], [5, 2, 1, 4], [2, 1]);
// => [1, 2, 3, 5, 4]
```
* * *
### `_.uniq(array, [isSorted=false], [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5350 "View in source") [Ⓣ][1]
Creates a duplicate-value-free version of an array using strict equality
for comparisons, i.e. `===`. If the array is sorted, providing
`true` for `isSorted` will use a faster algorithm. If a callback is provided
each element of `array` is passed through the callback before uniqueness
is computed. The callback is bound to `thisArg` and invoked with three
arguments; (value, index, array).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Aliases
*_.unique*
#### Arguments
1. `array` *(Array)*: The array to process.
2. `[isSorted=false]` *(boolean)*: A flag to indicate that `array` is sorted.
3. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
4. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Array)*: Returns a duplicate-value-free array.
#### Example
```js
_.uniq([1, 2, 1, 3, 1]);
// => [1, 2, 3]
_.uniq([1, 1, 2, 2, 3], true);
// => [1, 2, 3]
_.uniq(['A', 'b', 'C', 'a', 'B', 'c'], function(letter) { return letter.toLowerCase(); });
// => ['A', 'b', 'C']
_.uniq([1, 2.5, 3, 1.5, 2, 3.5], function(num) { return this.floor(num); }, Math);
// => [1, 2.5, 3]
// using "_.pluck" callback shorthand
_.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x');
// => [{ 'x': 1 }, { 'x': 2 }]
```
* * *
### `_.without(array, [value])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5378 "View in source") [Ⓣ][1]
Creates an array excluding all provided values using strict equality for
comparisons, i.e. `===`.
#### Arguments
1. `array` *(Array)*: The array to filter.
2. `[value]` *(...*)*: The values to exclude.
#### Returns
*(Array)*: Returns a new array of filtered values.
#### Example
```js
_.without([1, 2, 1, 0, 3, 1, 4], 0, 1);
// => [2, 3, 4]
```
* * *
### `_.xor([array])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5399 "View in source") [Ⓣ][1]
Creates an array that is the symmetric difference of the provided arrays.
See http://en.wikipedia.org/wiki/Symmetric_difference.
#### Arguments
1. `[array]` *(...Array)*: The arrays to inspect.
#### Returns
*(Array)*: Returns an array of values.
#### Example
```js
_.xor([1, 2, 3], [5, 2, 1, 4]);
// => [3, 5, 4]
_.xor([1, 2, 5], [2, 3, 5], [3, 4, 5]);
// => [1, 4, 5]
```
* * *
### `_.zip([array])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5430 "View in source") [Ⓣ][1]
Creates an array of grouped elements, the first of which contains the first
elements of the given arrays, the second of which contains the second
elements of the given arrays, and so on.
#### Aliases
*_.unzip*
#### Arguments
1. `[array]` *(...Array)*: Arrays to process.
#### Returns
*(Array)*: Returns a new array of grouped elements.
#### Example
```js
_.zip(['fred', 'barney'], [30, 40], [true, false]);
// => [['fred', 30, true], ['barney', 40, false]]
```
* * *
### `_.zipObject(keys, [values=[]])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5460 "View in source") [Ⓣ][1]
Creates an object composed from arrays of `keys` and `values`. Provide
either a single two dimensional array, i.e. `[[key1, value1], [key2, value2]]`
or two arrays, one of `keys` and one of corresponding `values`.
#### Aliases
*_.object*
#### Arguments
1. `keys` *(Array)*: The array of keys.
2. `[values=[]]` *(Array)*: The array of values.
#### Returns
*(Object)*: Returns an object composed of the given keys and
corresponding values.
#### Example
```js
_.zipObject(['fred', 'barney'], [30, 40]);
// => { 'fred': 30, 'barney': 40 }
```
* * *
## `“Chaining” Methods`
### `_(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L647 "View in source") [Ⓣ][1]
Creates a `lodash` object which wraps the given value to enable intuitive
method chaining.
In addition to Lo-Dash methods, wrappers also have the following `Array` methods:
`concat`, `join`, `pop`, `push`, `reverse`, `shift`, `slice`, `sort`, `splice`,
and `unshift`
Chaining is supported in custom builds as long as the `value` method is
implicitly or explicitly included in the build.
The chainable wrapper functions are:
`after`, `assign`, `bind`, `bindAll`, `bindKey`, `chain`, `compact`,
`compose`, `concat`, `countBy`, `create`, `createCallback`, `curry`,
`debounce`, `defaults`, `defer`, `delay`, `difference`, `filter`, `flatten`,
`forEach`, `forEachRight`, `forIn`, `forInRight`, `forOwn`, `forOwnRight`,
`functions`, `groupBy`, `indexBy`, `initial`, `intersection`, `invert`,
`invoke`, `keys`, `map`, `max`, `memoize`, `merge`, `min`, `object`, `omit`,
`once`, `pairs`, `partial`, `partialRight`, `pick`, `pluck`, `pull`, `push`,
`range`, `reject`, `remove`, `rest`, `reverse`, `shuffle`, `slice`, `sort`,
`sortBy`, `splice`, `tap`, `throttle`, `times`, `toArray`, `transform`,
`union`, `uniq`, `unshift`, `unzip`, `values`, `where`, `without`, `wrap`,
and `zip`
The non-chainable wrapper functions are:
`clone`, `cloneDeep`, `contains`, `escape`, `every`, `find`, `findIndex`,
`findKey`, `findLast`, `findLastIndex`, `findLastKey`, `has`, `identity`,
`indexOf`, `isArguments`, `isArray`, `isBoolean`, `isDate`, `isElement`,
`isEmpty`, `isEqual`, `isFinite`, `isFunction`, `isNaN`, `isNull`, `isNumber`,
`isObject`, `isPlainObject`, `isRegExp`, `isString`, `isUndefined`, `join`,
`lastIndexOf`, `mixin`, `noConflict`, `parseInt`, `pop`, `random`, `reduce`,
`reduceRight`, `result`, `shift`, `size`, `some`, `sortedIndex`, `runInContext`,
`template`, `unescape`, `uniqueId`, and `value`
The wrapper functions `first` and `last` return wrapped values when `n` is
provided, otherwise they return unwrapped values.
Explicit chaining can be enabled by using the `_.chain` method.
#### Arguments
1. `value` *(*)*: The value to wrap in a `lodash` instance.
#### Returns
*(Object)*: Returns a `lodash` instance.
#### Example
```js
var wrapped = _([1, 2, 3]);
// returns an unwrapped value
wrapped.reduce(function(sum, num) {
return sum + num;
});
// => 6
// returns a wrapped value
var squares = wrapped.map(function(num) {
return num * num;
});
_.isArray(squares);
// => false
_.isArray(squares.value());
// => true
```
* * *
### `_.chain(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6789 "View in source") [Ⓣ][1]
Creates a `lodash` object that wraps the given value with explicit
method chaining enabled.
#### Arguments
1. `value` *(*)*: The value to wrap.
#### Returns
*(Object)*: Returns the wrapper object.
#### Example
```js
var characters = [
{ 'name': 'barney', 'age': 36 },
{ 'name': 'fred', 'age': 40 },
{ 'name': 'pebbles', 'age': 1 }
];
var youngest = _.chain(characters)
.sortBy('age')
.map(function(chr) { return chr.name + ' is ' + chr.age; })
.first()
.value();
// => 'pebbles is 1'
```
* * *
### `_.tap(value, interceptor)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6815 "View in source") [Ⓣ][1]
Invokes `interceptor` with the `value` as the first argument and then
returns `value`. The purpose of this method is to "tap into" a method
chain in order to perform operations on intermediate results within
the chain.
#### Arguments
1. `value` *(*)*: The value to provide to `interceptor`.
2. `interceptor` *(Function)*: The function to invoke.
#### Returns
*(*)*: Returns `value`.
#### Example
```js
_([1, 2, 3, 4])
.tap(function(array) { array.pop(); })
.reverse()
.value();
// => [3, 2, 1]
```
* * *
### `_.prototype.chain()`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6845 "View in source") [Ⓣ][1]
Enables explicit method chaining on the wrapper object.
#### Returns
*(*)*: Returns the wrapper object.
#### Example
```js
var characters = [
{ 'name': 'barney', 'age': 36 },
{ 'name': 'fred', 'age': 40 }
];
// without explicit chaining
_(characters).first();
// => { 'name': 'barney', 'age': 36 }
// with explicit chaining
_(characters).chain()
.first()
.pick('age')
.value();
// => { 'age': 36 }
```
* * *
### `_.prototype.toString()`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6862 "View in source") [Ⓣ][1]
Produces the `toString` result of the wrapped value.
#### Returns
*(string)*: Returns the string result.
#### Example
```js
_([1, 2, 3]).toString();
// => '1,2,3'
```
* * *
### `_.prototype.valueOf()`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6879 "View in source") [Ⓣ][1]
Extracts the wrapped value.
#### Aliases
*_.prototype.value*
#### Returns
*(*)*: Returns the wrapped value.
#### Example
```js
_([1, 2, 3]).valueOf();
// => [1, 2, 3]
```
* * *
## `“Collections” Methods`
### `_.at(collection, [index])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3297 "View in source") [Ⓣ][1]
Creates an array of elements from the specified indexes, or keys, of the
`collection`. Indexes may be specified as individual arguments or as arrays
of indexes.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[index]` *(...(number|number[]|string|string[])*: The indexes of `collection` to retrieve, specified as individual indexes or arrays of indexes.
#### Returns
*(Array)*: Returns a new array of elements corresponding to the
provided indexes.
#### Example
```js
_.at(['a', 'b', 'c', 'd', 'e'], [0, 2, 4]);
// => ['a', 'c', 'e']
_.at(['fred', 'barney', 'pebbles'], 0, 2);
// => ['fred', 'pebbles']
```
* * *
### `_.contains(collection, target, [fromIndex=0])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3340 "View in source") [Ⓣ][1]
Checks if a given value is present in a collection using strict equality
for comparisons, i.e. `===`. If `fromIndex` is negative, it is used as the
offset from the end of the collection.
#### Aliases
*_.include*
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `target` *(*)*: The value to check for.
3. `[fromIndex=0]` *(number)*: The index to search from.
#### Returns
*(boolean)*: Returns `true` if the `target` element is found, else `false`.
#### Example
```js
_.contains([1, 2, 3], 1);
// => true
_.contains([1, 2, 3], 1, 2);
// => false
_.contains({ 'name': 'fred', 'age': 40 }, 'fred');
// => true
_.contains('pebbles', 'eb');
// => true
```
* * *
### `_.countBy(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3395 "View in source") [Ⓣ][1]
Creates an object composed of keys generated from the results of running
each element of `collection` through the callback. The corresponding value
of each key is the number of times the key was returned by the callback.
The callback is bound to `thisArg` and invoked with three arguments;
(value, index|key, collection).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Object)*: Returns the composed aggregate object.
#### Example
```js
_.countBy([4.3, 6.1, 6.4], function(num) { return Math.floor(num); });
// => { '4': 1, '6': 2 }
_.countBy([4.3, 6.1, 6.4], function(num) { return this.floor(num); }, Math);
// => { '4': 1, '6': 2 }
_.countBy(['one', 'two', 'three'], 'length');
// => { '3': 2, '5': 1 }
```
* * *
### `_.every(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3440 "View in source") [Ⓣ][1]
Checks if the given callback returns truey value for **all** elements of
a collection. The callback is bound to `thisArg` and invoked with three
arguments; (value, index|key, collection).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Aliases
*_.all*
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(boolean)*: Returns `true` if all elements passed the callback check,
else `false`.
#### Example
```js
_.every([true, 1, null, 'yes']);
// => false
var characters = [
{ 'name': 'barney', 'age': 36 },
{ 'name': 'fred', 'age': 40 }
];
// using "_.pluck" callback shorthand
_.every(characters, 'age');
// => true
// using "_.where" callback shorthand
_.every(characters, { 'age': 36 });
// => false
```
* * *
### `_.filter(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3501 "View in source") [Ⓣ][1]
Iterates over elements of a collection, returning an array of all elements
the callback returns truey for. The callback is bound to `thisArg` and
invoked with three arguments; (value, index|key, collection).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Aliases
*_.select*
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Array)*: Returns a new array of elements that passed the callback check.
#### Example
```js
var evens = _.filter([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
// => [2, 4, 6]
var characters = [
{ 'name': 'barney', 'age': 36, 'blocked': false },
{ 'name': 'fred', 'age': 40, 'blocked': true }
];
// using "_.pluck" callback shorthand
_.filter(characters, 'blocked');
// => [{ 'name': 'fred', 'age': 40, 'blocked': true }]
// using "_.where" callback shorthand
_.filter(characters, { 'age': 36 });
// => [{ 'name': 'barney', 'age': 36, 'blocked': false }]
```
* * *
### `_.find(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3568 "View in source") [Ⓣ][1]
Iterates over elements of a collection, returning the first element that
the callback returns truey for. The callback is bound to `thisArg` and
invoked with three arguments; (value, index|key, collection).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Aliases
*_.detect, _.findWhere*
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(*)*: Returns the found element, else `undefined`.
#### Example
```js
var characters = [
{ 'name': 'barney', 'age': 36, 'blocked': false },
{ 'name': 'fred', 'age': 40, 'blocked': true },
{ 'name': 'pebbles', 'age': 1, 'blocked': false }
];
_.find(characters, function(chr) {
return chr.age < 40;
});
// => { 'name': 'barney', 'age': 36, 'blocked': false }
// using "_.where" callback shorthand
_.find(characters, { 'age': 1 });
// => { 'name': 'pebbles', 'age': 1, 'blocked': false }
// using "_.pluck" callback shorthand
_.find(characters, 'blocked');
// => { 'name': 'fred', 'age': 40, 'blocked': true }
```
* * *
### `_.findLast(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3613 "View in source") [Ⓣ][1]
This method is like `_.find` except that it iterates over elements
of a `collection` from right to left.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(*)*: Returns the found element, else `undefined`.
#### Example
```js
_.findLast([1, 2, 3, 4], function(num) {
return num % 2 == 1;
});
// => 3
```
* * *
### `_.forEach(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3651 "View in source") [Ⓣ][1]
Iterates over elements of a collection, executing the callback for each
element. The callback is bound to `thisArg` and invoked with three arguments;
(value, index|key, collection). Callbacks may exit iteration early by
explicitly returning `false`.
Note: As with other "Collections" methods, objects with a `length` property
are iterated like arrays. To avoid this behavior `_.forIn` or `_.forOwn`
may be used for object iteration.
#### Aliases
*_.each*
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function)*: The function called per iteration.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Array|Object|string)*: Returns `collection`.
#### Example
```js
_([1, 2, 3]).forEach(function(num) { console.log(num); }).join(',');
// => logs each number and returns '1,2,3'
_.forEach({ 'one': 1, 'two': 2, 'three': 3 }, function(num) { console.log(num); });
// => logs each number and returns the object (property order is not guaranteed across environments)
```
* * *
### `_.forEachRight(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3684 "View in source") [Ⓣ][1]
This method is like `_.forEach` except that it iterates over elements
of a `collection` from right to left.
#### Aliases
*_.eachRight*
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function)*: The function called per iteration.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Array|Object|string)*: Returns `collection`.
#### Example
```js
_([1, 2, 3]).forEachRight(function(num) { console.log(num); }).join(',');
// => logs each number from right to left and returns '3,2,1'
```
* * *
### `_.groupBy(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3745 "View in source") [Ⓣ][1]
Creates an object composed of keys generated from the results of running
each element of a collection through the callback. The corresponding value
of each key is an array of the elements responsible for generating the key.
The callback is bound to `thisArg` and invoked with three arguments;
(value, index|key, collection).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Object)*: Returns the composed aggregate object.
#### Example
```js
_.groupBy([4.2, 6.1, 6.4], function(num) { return Math.floor(num); });
// => { '4': [4.2], '6': [6.1, 6.4] }
_.groupBy([4.2, 6.1, 6.4], function(num) { return this.floor(num); }, Math);
// => { '4': [4.2], '6': [6.1, 6.4] }
// using "_.pluck" callback shorthand
_.groupBy(['one', 'two', 'three'], 'length');
// => { '3': ['one', 'two'], '5': ['three'] }
```
* * *
### `_.indexBy(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3788 "View in source") [Ⓣ][1]
Creates an object composed of keys generated from the results of running
each element of the collection through the given callback. The corresponding
value of each key is the last element responsible for generating the key.
The callback is bound to `thisArg` and invoked with three arguments;
(value, index|key, collection).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Object)*: Returns the composed aggregate object.
#### Example
```js
var keys = [
{ 'dir': 'left', 'code': 97 },
{ 'dir': 'right', 'code': 100 }
];
_.indexBy(keys, 'dir');
// => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } }
_.indexBy(keys, function(key) { return String.fromCharCode(key.code); });
// => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }
_.indexBy(characters, function(key) { this.fromCharCode(key.code); }, String);
// => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }
```
* * *
### `_.invoke(collection, methodName, [arg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3814 "View in source") [Ⓣ][1]
Invokes the method named by `methodName` on each element in the `collection`
returning an array of the results of each invoked method. Additional arguments
will be provided to each invoked method. If `methodName` is a function it
will be invoked for, and `this` bound to, each element in the `collection`.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `methodName` *(Function|string)*: The name of the method to invoke or the function invoked per iteration.
3. `[arg]` *(...*)*: Arguments to invoke the method with.
#### Returns
*(Array)*: Returns a new array of the results of each invoked method.
#### Example
```js
_.invoke([[5, 1, 7], [3, 2, 1]], 'sort');
// => [[1, 5, 7], [1, 2, 3]]
_.invoke([123, 456], String.prototype.split, '');
// => [['1', '2', '3'], ['4', '5', '6']]
```
* * *
### `_.map(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3866 "View in source") [Ⓣ][1]
Creates an array of values by running each element in the collection
through the callback. The callback is bound to `thisArg` and invoked with
three arguments; (value, index|key, collection).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Aliases
*_.collect*
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Array)*: Returns a new array of the results of each `callback` execution.
#### Example
```js
_.map([1, 2, 3], function(num) { return num * 3; });
// => [3, 6, 9]
_.map({ 'one': 1, 'two': 2, 'three': 3 }, function(num) { return num * 3; });
// => [3, 6, 9] (property order is not guaranteed across environments)
var characters = [
{ 'name': 'barney', 'age': 36 },
{ 'name': 'fred', 'age': 40 }
];
// using "_.pluck" callback shorthand
_.map(characters, 'name');
// => ['barney', 'fred']
```
* * *
### `_.max(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3924 "View in source") [Ⓣ][1]
Retrieves the maximum value of a collection. If the collection is empty or
falsey `-Infinity` is returned. If a callback is provided it will be executed
for each value in the collection to generate the criterion by which the value
is ranked. The callback is bound to `thisArg` and invoked with three
arguments; (value, index, collection).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(*)*: Returns the maximum value.
#### Example
```js
_.max([4, 2, 8, 6]);
// => 8
var characters = [
{ 'name': 'barney', 'age': 36 },
{ 'name': 'fred', 'age': 40 }
];
_.max(characters, function(chr) { return chr.age; });
// => { 'name': 'fred', 'age': 40 };
// using "_.pluck" callback shorthand
_.max(characters, 'age');
// => { 'name': 'fred', 'age': 40 };
```
* * *
### `_.min(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3999 "View in source") [Ⓣ][1]
Retrieves the minimum value of a collection. If the collection is empty or
falsey `Infinity` is returned. If a callback is provided it will be executed
for each value in the collection to generate the criterion by which the value
is ranked. The callback is bound to `thisArg` and invoked with three
arguments; (value, index, collection).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(*)*: Returns the minimum value.
#### Example
```js
_.min([4, 2, 8, 6]);
// => 2
var characters = [
{ 'name': 'barney', 'age': 36 },
{ 'name': 'fred', 'age': 40 }
];
_.min(characters, function(chr) { return chr.age; });
// => { 'name': 'barney', 'age': 36 };
// using "_.pluck" callback shorthand
_.min(characters, 'age');
// => { 'name': 'barney', 'age': 36 };
```
* * *
### `_.pluck(collection, property)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4054 "View in source") [Ⓣ][1]
Retrieves the value of a specified property from all elements in the collection.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `property` *(string)*: The name of the property to pluck.
#### Returns
*(Array)*: Returns a new array of property values.
#### Example
```js
var characters = [
{ 'name': 'barney', 'age': 36 },
{ 'name': 'fred', 'age': 40 }
];
_.pluck(characters, 'name');
// => ['barney', 'fred']
```
* * *
### `_.reduce(collection, [callback=identity], [accumulator], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4086 "View in source") [Ⓣ][1]
Reduces a collection to a value which is the accumulated result of running
each element in the collection through the callback, where each successive
callback execution consumes the return value of the previous execution. If
`accumulator` is not provided the first element of the collection will be
used as the initial `accumulator` value. The callback is bound to `thisArg`
and invoked with four arguments; (accumulator, value, index|key, collection).
#### Aliases
*_.foldl, _.inject*
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function)*: The function called per iteration.
3. `[accumulator]` *(*)*: Initial value of the accumulator.
4. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(*)*: Returns the accumulated value.
#### Example
```js
var sum = _.reduce([1, 2, 3], function(sum, num) {
return sum + num;
});
// => 6
var mapped = _.reduce({ 'a': 1, 'b': 2, 'c': 3 }, function(result, num, key) {
result[key] = num * 3;
return result;
}, {});
// => { 'a': 3, 'b': 6, 'c': 9 }
```
* * *
### `_.reduceRight(collection, [callback=identity], [accumulator], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4129 "View in source") [Ⓣ][1]
This method is like `_.reduce` except that it iterates over elements
of a `collection` from right to left.
#### Aliases
*_.foldr*
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function)*: The function called per iteration.
3. `[accumulator]` *(*)*: Initial value of the accumulator.
4. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(*)*: Returns the accumulated value.
#### Example
```js
var list = [[0, 1], [2, 3], [4, 5]];
var flat = _.reduceRight(list, function(a, b) { return a.concat(b); }, []);
// => [4, 5, 2, 3, 0, 1]
```
* * *
### `_.reject(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4178 "View in source") [Ⓣ][1]
The opposite of `_.filter` this method returns the elements of a
collection that the callback does **not** return truey for.
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Array)*: Returns a new array of elements that failed the callback check.
#### Example
```js
var odds = _.reject([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
// => [1, 3, 5]
var characters = [
{ 'name': 'barney', 'age': 36, 'blocked': false },
{ 'name': 'fred', 'age': 40, 'blocked': true }
];
// using "_.pluck" callback shorthand
_.reject(characters, 'blocked');
// => [{ 'name': 'barney', 'age': 36, 'blocked': false }]
// using "_.where" callback shorthand
_.reject(characters, { 'age': 36 });
// => [{ 'name': 'fred', 'age': 40, 'blocked': true }]
```
* * *
### `_.sample(collection, [n])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4204 "View in source") [Ⓣ][1]
Retrieves a random element or `n` random elements from a collection.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to sample.
2. `[n]` *(number)*: The number of elements to sample.
#### Returns
*(Array)*: Returns the random sample(s) of `collection`.
#### Example
```js
_.sample([1, 2, 3, 4]);
// => 2
_.sample([1, 2, 3, 4], 2);
// => [3, 1]
```
* * *
### `_.shuffle(collection)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4232 "View in source") [Ⓣ][1]
Creates an array of shuffled values, using a version of the Fisher-Yates
shuffle. See http://en.wikipedia.org/wiki/Fisher-Yates_shuffle.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to shuffle.
#### Returns
*(Array)*: Returns a new shuffled collection.
#### Example
```js
_.shuffle([1, 2, 3, 4, 5, 6]);
// => [4, 1, 6, 3, 5, 2]
```
* * *
### `_.size(collection)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4265 "View in source") [Ⓣ][1]
Gets the size of the `collection` by returning `collection.length` for arrays
and array-like objects or the number of own enumerable properties for objects.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to inspect.
#### Returns
*(number)*: Returns `collection.length` or number of own enumerable properties.
#### Example
```js
_.size([1, 2]);
// => 2
_.size({ 'one': 1, 'two': 2, 'three': 3 });
// => 3
_.size('pebbles');
// => 7
```
* * *
### `_.some(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4312 "View in source") [Ⓣ][1]
Checks if the callback returns a truey value for **any** element of a
collection. The function returns as soon as it finds a passing value and
does not iterate over the entire collection. The callback is bound to
`thisArg` and invoked with three arguments; (value, index|key, collection).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Aliases
*_.any*
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(boolean)*: Returns `true` if any element passed the callback check,
else `false`.
#### Example
```js
_.some([null, 0, 'yes', false], Boolean);
// => true
var characters = [
{ 'name': 'barney', 'age': 36, 'blocked': false },
{ 'name': 'fred', 'age': 40, 'blocked': true }
];
// using "_.pluck" callback shorthand
_.some(characters, 'blocked');
// => true
// using "_.where" callback shorthand
_.some(characters, { 'age': 1 });
// => false
```
* * *
### `_.sortBy(collection, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4382 "View in source") [Ⓣ][1]
Creates an array of elements, sorted in ascending order by the results of
running each element in a collection through the callback. This method
performs a stable sort, that is, it will preserve the original sort order
of equal elements. The callback is bound to `thisArg` and invoked with
three arguments; (value, index|key, collection).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an array of property names is provided for `callback` the collection
will be sorted by each property value.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `[callback=identity]` *(Array|Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Array)*: Returns a new array of sorted elements.
#### Example
```js
_.sortBy([1, 2, 3], function(num) { return Math.sin(num); });
// => [3, 1, 2]
_.sortBy([1, 2, 3], function(num) { return this.sin(num); }, Math);
// => [3, 1, 2]
var characters = [
{ 'name': 'barney', 'age': 36 },
{ 'name': 'fred', 'age': 40 },
{ 'name': 'barney', 'age': 26 },
{ 'name': 'fred', 'age': 30 }
];
// using "_.pluck" callback shorthand
_.map(_.sortBy(characters, 'age'), _.values);
// => [['barney', 26], ['fred', 30], ['barney', 36], ['fred', 40]]
// sorting by multiple properties
_.map(_.sortBy(characters, ['name', 'age']), _.values);
// = > [['barney', 26], ['barney', 36], ['fred', 30], ['fred', 40]]
```
* * *
### `_.toArray(collection)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4428 "View in source") [Ⓣ][1]
Converts the `collection` to an array.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to convert.
#### Returns
*(Array)*: Returns the new converted array.
#### Example
```js
(function() { return _.toArray(arguments).slice(1); })(1, 2, 3, 4);
// => [2, 3, 4]
```
* * *
### `_.where(collection, props)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L4462 "View in source") [Ⓣ][1]
Performs a deep comparison of each element in a `collection` to the given
`properties` object, returning an array of all elements that have equivalent
property values.
#### Arguments
1. `collection` *(Array|Object|string)*: The collection to iterate over.
2. `props` *(Object)*: The object of property values to filter by.
#### Returns
*(Array)*: Returns a new array of elements that have the given properties.
#### Example
```js
var characters = [
{ 'name': 'barney', 'age': 36, 'pets': ['hoppy'] },
{ 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] }
];
_.where(characters, { 'age': 36 });
// => [{ 'name': 'barney', 'age': 36, 'pets': ['hoppy'] }]
_.where(characters, { 'pets': ['dino'] });
// => [{ 'name': 'fred', 'age': 40, 'pets': ['baby puss', 'dino'] }]
```
* * *
## `“Functions” Methods`
### `_.after(n, func)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5505 "View in source") [Ⓣ][1]
Creates a function that executes `func`, with the `this` binding and
arguments of the created function, only after being called `n` times.
#### Arguments
1. `n` *(number)*: The number of times the function must be called before `func` is executed.
2. `func` *(Function)*: The function to restrict.
#### Returns
*(Function)*: Returns the new restricted function.
#### Example
```js
var saves = ['profile', 'settings'];
var done = _.after(saves.length, function() {
console.log('Done saving!');
});
_.forEach(saves, function(type) {
asyncSave({ 'type': type, 'complete': done });
});
// => logs 'Done saving!', after all saves have completed
```
* * *
### `_.bind(func, [thisArg], [arg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5538 "View in source") [Ⓣ][1]
Creates a function that, when called, invokes `func` with the `this`
binding of `thisArg` and prepends any additional `bind` arguments to those
provided to the bound function.
#### Arguments
1. `func` *(Function)*: The function to bind.
2. `[thisArg]` *(*)*: The `this` binding of `func`.
3. `[arg]` *(...*)*: Arguments to be partially applied.
#### Returns
*(Function)*: Returns the new bound function.
#### Example
```js
var func = function(greeting) {
return greeting + ' ' + this.name;
};
func = _.bind(func, { 'name': 'fred' }, 'hi');
func();
// => 'hi fred'
```
* * *
### `_.bindAll(object, [methodName])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5568 "View in source") [Ⓣ][1]
Binds methods of an object to the object itself, overwriting the existing
method. Method names may be specified as individual arguments or as arrays
of method names. If no method names are provided all the function properties
of `object` will be bound.
#### Arguments
1. `object` *(Object)*: The object to bind and assign the bound methods to.
2. `[methodName]` *(...string)*: The object method names to bind, specified as individual method names or arrays of method names.
#### Returns
*(Object)*: Returns `object`.
#### Example
```js
var view = {
'label': 'docs',
'onClick': function() { console.log('clicked ' + this.label); }
};
_.bindAll(view);
jQuery('#docs').on('click', view.onClick);
// => logs 'clicked docs', when the button is clicked
```
* * *
### `_.bindKey(object, key, [arg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5614 "View in source") [Ⓣ][1]
Creates a function that, when called, invokes the method at `object[key]`
and prepends any additional `bindKey` arguments to those provided to the bound
function. This method differs from `_.bind` by allowing bound functions to
reference methods that will be redefined or don't yet exist.
See http://michaux.ca/articles/lazy-function-definition-pattern.
#### Arguments
1. `object` *(Object)*: The object the method belongs to.
2. `key` *(string)*: The key of the method.
3. `[arg]` *(...*)*: Arguments to be partially applied.
#### Returns
*(Function)*: Returns the new bound function.
#### Example
```js
var object = {
'name': 'fred',
'greet': function(greeting) {
return greeting + ' ' + this.name;
}
};
var func = _.bindKey(object, 'greet', 'hi');
func();
// => 'hi fred'
object.greet = function(greeting) {
return greeting + 'ya ' + this.name + '!';
};
func();
// => 'hiya fred!'
```
* * *
### `_.compose([func])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5650 "View in source") [Ⓣ][1]
Creates a function that is the composition of the provided functions,
where each function consumes the return value of the function that follows.
For example, composing the functions `f()`, `g()`, and `h()` produces `f(g(h()))`.
Each function is executed with the `this` binding of the composed function.
#### Arguments
1. `[func]` *(...Function)*: Functions to compose.
#### Returns
*(Function)*: Returns the new composed function.
#### Example
```js
var realNameMap = {
'pebbles': 'penelope'
};
var format = function(name) {
name = realNameMap[name.toLowerCase()] || name;
return name.charAt(0).toUpperCase() + name.slice(1).toLowerCase();
};
var greet = function(formatted) {
return 'Hiya ' + formatted + '!';
};
var welcome = _.compose(greet, format);
welcome('pebbles');
// => 'Hiya Penelope!'
```
* * *
### `_.curry(func, [arity=func.length])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5698 "View in source") [Ⓣ][1]
Creates a function which accepts one or more arguments of `func` that when
invoked either executes `func` returning its result, if all `func` arguments
have been provided, or returns a function that accepts one or more of the
remaining `func` arguments, and so on. The arity of `func` can be specified
if `func.length` is not sufficient.
#### Arguments
1. `func` *(Function)*: The function to curry.
2. `[arity=func.length]` *(number)*: The arity of `func`.
#### Returns
*(Function)*: Returns the new curried function.
#### Example
```js
var curried = _.curry(function(a, b, c) {
console.log(a + b + c);
});
curried(1)(2)(3);
// => 6
curried(1, 2)(3);
// => 6
curried(1, 2, 3);
// => 6
```
* * *
### `_.debounce(func, wait, [options])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5742 "View in source") [Ⓣ][1]
Creates a function that will delay the execution of `func` until after
`wait` milliseconds have elapsed since the last time it was invoked.
Provide an options object to indicate that `func` should be invoked on
the leading and/or trailing edge of the `wait` timeout. Subsequent calls
to the debounced function will return the result of the last `func` call.
Note: If `leading` and `trailing` options are `true` `func` will be called
on the trailing edge of the timeout only if the the debounced function is
invoked more than once during the `wait` timeout.
#### Arguments
1. `func` *(Function)*: The function to debounce.
2. `wait` *(number)*: The number of milliseconds to delay.
3. `[options]` *(Object)*: The options object.
4. `[options.leading=false]` *(boolean)*: Specify execution on the leading edge of the timeout.
5. `[options.maxWait]` *(number)*: The maximum time `func` is allowed to be delayed before it's called.
6. `[options.trailing=true]` *(boolean)*: Specify execution on the trailing edge of the timeout.
#### Returns
*(Function)*: Returns the new debounced function.
#### Example
```js
// avoid costly calculations while the window size is in flux
var lazyLayout = _.debounce(calculateLayout, 150);
jQuery(window).on('resize', lazyLayout);
// execute `sendMail` when the click event is fired, debouncing subsequent calls
jQuery('#postbox').on('click', _.debounce(sendMail, 300, {
'leading': true,
'trailing': false
});
// ensure `batchLog` is executed once after 1 second of debounced calls
var source = new EventSource('/stream');
source.addEventListener('message', _.debounce(batchLog, 250, {
'maxWait': 1000
}, false);
```
* * *
### `_.defer(func, [arg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5858 "View in source") [Ⓣ][1]
Defers executing the `func` function until the current call stack has cleared.
Additional arguments will be provided to `func` when it is invoked.
#### Arguments
1. `func` *(Function)*: The function to defer.
2. `[arg]` *(...*)*: Arguments to invoke the function with.
#### Returns
*(number)*: Returns the timer id.
#### Example
```js
_.defer(function(text) { console.log(text); }, 'deferred');
// logs 'deferred' after one or more milliseconds
```
* * *
### `_.delay(func, wait, [arg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5882 "View in source") [Ⓣ][1]
Executes the `func` function after `wait` milliseconds. Additional arguments
will be provided to `func` when it is invoked.
#### Arguments
1. `func` *(Function)*: The function to delay.
2. `wait` *(number)*: The number of milliseconds to delay execution.
3. `[arg]` *(...*)*: Arguments to invoke the function with.
#### Returns
*(number)*: Returns the timer id.
#### Example
```js
_.delay(function(text) { console.log(text); }, 1000, 'later');
// => logs 'later' after one second
```
* * *
### `_.memoize(func, [resolver])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5927 "View in source") [Ⓣ][1]
Creates a function that memoizes the result of `func`. If `resolver` is
provided it will be used to determine the cache key for storing the result
based on the arguments provided to the memoized function. By default, the
first argument provided to the memoized function is used as the cache key.
The `func` is executed with the `this` binding of the memoized function.
The result cache is exposed as the `cache` property on the memoized function.
#### Arguments
1. `func` *(Function)*: The function to have its output memoized.
2. `[resolver]` *(Function)*: A function used to resolve the cache key.
#### Returns
*(Function)*: Returns the new memoizing function.
#### Example
```js
var fibonacci = _.memoize(function(n) {
return n < 2 ? n : fibonacci(n - 1) + fibonacci(n - 2);
});
fibonacci(9)
// => 34
var data = {
'fred': { 'name': 'fred', 'age': 40 },
'pebbles': { 'name': 'pebbles', 'age': 1 }
};
// modifying the result cache
var get = _.memoize(function(name) { return data[name]; }, _.identity);
get('pebbles');
// => { 'name': 'pebbles', 'age': 1 }
get.cache.pebbles.name = 'penelope';
get('pebbles');
// => { 'name': 'penelope', 'age': 1 }
```
* * *
### `_.once(func)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5960 "View in source") [Ⓣ][1]
Creates a function that is restricted to execute `func` once. Repeat calls to
the function will return the value of the first call. The `func` is executed
with the `this` binding of the created function.
#### Arguments
1. `func` *(Function)*: The function to restrict.
#### Returns
*(Function)*: Returns the new restricted function.
#### Example
```js
var initialize = _.once(createApplication);
initialize();
initialize();
// `initialize` executes `createApplication` once
```
* * *
### `_.partial(func, [arg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L5998 "View in source") [Ⓣ][1]
Creates a function that, when called, invokes `func` with any additional
`partial` arguments prepended to those provided to the new function. This
method is similar to `_.bind` except it does **not** alter the `this` binding.
#### Arguments
1. `func` *(Function)*: The function to partially apply arguments to.
2. `[arg]` *(...*)*: Arguments to be partially applied.
#### Returns
*(Function)*: Returns the new partially applied function.
#### Example
```js
var greet = function(greeting, name) { return greeting + ' ' + name; };
var hi = _.partial(greet, 'hi');
hi('fred');
// => 'hi fred'
```
* * *
### `_.partialRight(func, [arg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6029 "View in source") [Ⓣ][1]
This method is like `_.partial` except that `partial` arguments are
appended to those provided to the new function.
#### Arguments
1. `func` *(Function)*: The function to partially apply arguments to.
2. `[arg]` *(...*)*: Arguments to be partially applied.
#### Returns
*(Function)*: Returns the new partially applied function.
#### Example
```js
var defaultsDeep = _.partialRight(_.merge, _.defaults);
var options = {
'variable': 'data',
'imports': { 'jq': $ }
};
defaultsDeep(options, _.templateSettings);
options.variable
// => 'data'
options.imports
// => { '_': _, 'jq': $ }
```
* * *
### `_.throttle(func, wait, [options])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6064 "View in source") [Ⓣ][1]
Creates a function that, when executed, will only call the `func` function
at most once per every `wait` milliseconds. Provide an options object to
indicate that `func` should be invoked on the leading and/or trailing edge
of the `wait` timeout. Subsequent calls to the throttled function will
return the result of the last `func` call.
Note: If `leading` and `trailing` options are `true` `func` will be called
on the trailing edge of the timeout only if the the throttled function is
invoked more than once during the `wait` timeout.
#### Arguments
1. `func` *(Function)*: The function to throttle.
2. `wait` *(number)*: The number of milliseconds to throttle executions to.
3. `[options]` *(Object)*: The options object.
4. `[options.leading=true]` *(boolean)*: Specify execution on the leading edge of the timeout.
5. `[options.trailing=true]` *(boolean)*: Specify execution on the trailing edge of the timeout.
#### Returns
*(Function)*: Returns the new throttled function.
#### Example
```js
// avoid excessively updating the position while scrolling
var throttled = _.throttle(updatePosition, 100);
jQuery(window).on('scroll', throttled);
// execute `renewToken` when the click event is fired, but not more than once every 5 minutes
jQuery('.interactive').on('click', _.throttle(renewToken, 300000, {
'trailing': false
}));
```
* * *
### `_.wrap(value, wrapper)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6105 "View in source") [Ⓣ][1]
Creates a function that provides `value` to the wrapper function as its
first argument. Additional arguments provided to the function are appended
to those provided to the wrapper function. The wrapper is executed with
the `this` binding of the created function.
#### Arguments
1. `value` *(*)*: The value to wrap.
2. `wrapper` *(Function)*: The wrapper function.
#### Returns
*(Function)*: Returns the new function.
#### Example
```js
var p = _.wrap(_.escape, function(func, text) {
return '' + func(text) + '
';
});
p('Fred, Wilma, & Pebbles');
// => 'Fred, Wilma, & Pebbles
'
```
* * *
## `“Objects” Methods`
### `_.assign(object, [source], [callback], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2085 "View in source") [Ⓣ][1]
Assigns own enumerable properties of source object(s) to the destination
object. Subsequent sources will overwrite property assignments of previous
sources. If a callback is provided it will be executed to produce the
assigned values. The callback is bound to `thisArg` and invoked with two
arguments; (objectValue, sourceValue).
#### Aliases
*_.extend*
#### Arguments
1. `object` *(Object)*: The destination object.
2. `[source]` *(...Object)*: The source objects.
3. `[callback]` *(Function)*: The function to customize assigning values.
4. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Object)*: Returns the destination object.
#### Example
```js
_.assign({ 'name': 'fred' }, { 'employer': 'slate' });
// => { 'name': 'fred', 'employer': 'slate' }
var defaults = _.partialRight(_.assign, function(a, b) {
return typeof a == 'undefined' ? b : a;
});
var object = { 'name': 'barney' };
defaults(object, { 'name': 'fred', 'employer': 'slate' });
// => { 'name': 'barney', 'employer': 'slate' }
```
* * *
### `_.clone(value, [isDeep=false], [callback], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2138 "View in source") [Ⓣ][1]
Creates a clone of `value`. If `isDeep` is `true` nested objects will also
be cloned, otherwise they will be assigned by reference. If a callback
is provided it will be executed to produce the cloned values. If the
callback returns `undefined` cloning will be handled by the method instead.
The callback is bound to `thisArg` and invoked with one argument; (value).
#### Arguments
1. `value` *(*)*: The value to clone.
2. `[isDeep=false]` *(boolean)*: Specify a deep clone.
3. `[callback]` *(Function)*: The function to customize cloning values.
4. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(*)*: Returns the cloned value.
#### Example
```js
var characters = [
{ 'name': 'barney', 'age': 36 },
{ 'name': 'fred', 'age': 40 }
];
var shallow = _.clone(characters);
shallow[0] === characters[0];
// => true
var deep = _.clone(characters, true);
deep[0] === characters[0];
// => false
_.mixin({
'clone': _.partialRight(_.clone, function(value) {
return _.isElement(value) ? value.cloneNode(false) : undefined;
})
});
var clone = _.clone(document.body);
clone.childNodes.length;
// => 0
```
* * *
### `_.cloneDeep(value, [callback], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2190 "View in source") [Ⓣ][1]
Creates a deep clone of `value`. If a callback is provided it will be
executed to produce the cloned values. If the callback returns `undefined`
cloning will be handled by the method instead. The callback is bound to
`thisArg` and invoked with one argument; (value).
Note: This method is loosely based on the structured clone algorithm. Functions
and DOM nodes are **not** cloned. The enumerable properties of `arguments` objects and
objects created by constructors other than `Object` are cloned to plain `Object` objects.
See http://www.w3.org/TR/html5/infrastructure.html#internal-structured-cloning-algorithm.
#### Arguments
1. `value` *(*)*: The value to deep clone.
2. `[callback]` *(Function)*: The function to customize cloning values.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(*)*: Returns the deep cloned value.
#### Example
```js
var characters = [
{ 'name': 'barney', 'age': 36 },
{ 'name': 'fred', 'age': 40 }
];
var deep = _.cloneDeep(characters);
deep[0] === characters[0];
// => false
var view = {
'label': 'docs',
'node': element
};
var clone = _.cloneDeep(view, function(value) {
return _.isElement(value) ? value.cloneNode(true) : undefined;
});
clone.node == view.node;
// => false
```
* * *
### `_.create(prototype, [properties])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2225 "View in source") [Ⓣ][1]
Creates an object that inherits from the given `prototype` object. If a
`properties` object is provided its own enumerable properties are assigned
to the created object.
#### Arguments
1. `prototype` *(Object)*: The object to inherit from.
2. `[properties]` *(Object)*: The properties to assign to the object.
#### Returns
*(Object)*: Returns the new object.
#### Example
```js
function Shape() {
this.x = 0;
this.y = 0;
}
function Circle() {
Shape.call(this);
}
Circle.prototype = _.create(Shape.prototype, { 'constructor': Circle });
var circle = new Circle;
circle instanceof Circle;
// => true
circle instanceof Shape;
// => true
```
* * *
### `_.defaults(object, [source])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2250 "View in source") [Ⓣ][1]
Assigns own enumerable properties of source object(s) to the destination
object for all destination properties that resolve to `undefined`. Once a
property is set, additional defaults of the same property will be ignored.
#### Arguments
1. `object` *(Object)*: The destination object.
2. `[source]` *(...Object)*: The source objects.
#### Returns
*(Object)*: Returns the destination object.
#### Example
```js
var object = { 'name': 'barney' };
_.defaults(object, { 'name': 'fred', 'employer': 'slate' });
// => { 'name': 'barney', 'employer': 'slate' }
```
* * *
### `_.findKey(object, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2293 "View in source") [Ⓣ][1]
This method is like `_.findIndex` except that it returns the key of the
first element that passes the callback check, instead of the element itself.
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `object` *(Object)*: The object to search.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(string|undefined)*: Returns the key of the found element, else `undefined`.
#### Example
```js
var characters = {
'barney': { 'age': 36, 'blocked': false },
'fred': { 'age': 40, 'blocked': true },
'pebbles': { 'age': 1, 'blocked': false }
};
_.findKey(characters, function(chr) {
return chr.age < 40;
});
// => 'barney' (property order is not guaranteed across environments)
// using "_.where" callback shorthand
_.findKey(characters, { 'age': 1 });
// => 'pebbles'
// using "_.pluck" callback shorthand
_.findKey(characters, 'blocked');
// => 'fred'
```
* * *
### `_.findLastKey(object, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2346 "View in source") [Ⓣ][1]
This method is like `_.findKey` except that it iterates over elements
of a `collection` in the opposite order.
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `object` *(Object)*: The object to search.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(string|undefined)*: Returns the key of the found element, else `undefined`.
#### Example
```js
var characters = {
'barney': { 'age': 36, 'blocked': true },
'fred': { 'age': 40, 'blocked': false },
'pebbles': { 'age': 1, 'blocked': true }
};
_.findLastKey(characters, function(chr) {
return chr.age < 40;
});
// => returns `pebbles`, assuming `_.findKey` returns `barney`
// using "_.where" callback shorthand
_.findLastKey(characters, { 'age': 40 });
// => 'fred'
// using "_.pluck" callback shorthand
_.findLastKey(characters, 'blocked');
// => 'pebbles'
```
* * *
### `_.forIn(object, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2389 "View in source") [Ⓣ][1]
Iterates over own and inherited enumerable properties of an object,
executing the callback for each property. The callback is bound to `thisArg`
and invoked with three arguments; (value, key, object). Callbacks may exit
iteration early by explicitly returning `false`.
#### Arguments
1. `object` *(Object)*: The object to iterate over.
2. `[callback=identity]` *(Function)*: The function called per iteration.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Object)*: Returns `object`.
#### Example
```js
function Shape() {
this.x = 0;
this.y = 0;
}
Shape.prototype.move = function(x, y) {
this.x += x;
this.y += y;
};
_.forIn(new Shape, function(value, key) {
console.log(key);
});
// => logs 'x', 'y', and 'move' (property order is not guaranteed across environments)
```
* * *
### `_.forInRight(object, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2421 "View in source") [Ⓣ][1]
This method is like `_.forIn` except that it iterates over elements
of a `collection` in the opposite order.
#### Arguments
1. `object` *(Object)*: The object to iterate over.
2. `[callback=identity]` *(Function)*: The function called per iteration.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Object)*: Returns `object`.
#### Example
```js
function Shape() {
this.x = 0;
this.y = 0;
}
Shape.prototype.move = function(x, y) {
this.x += x;
this.y += y;
};
_.forInRight(new Shape, function(value, key) {
console.log(key);
});
// => logs 'move', 'y', and 'x' assuming `_.forIn ` logs 'x', 'y', and 'move'
```
* * *
### `_.forOwn(object, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2459 "View in source") [Ⓣ][1]
Iterates over own enumerable properties of an object, executing the callback
for each property. The callback is bound to `thisArg` and invoked with three
arguments; (value, key, object). Callbacks may exit iteration early by
explicitly returning `false`.
#### Arguments
1. `object` *(Object)*: The object to iterate over.
2. `[callback=identity]` *(Function)*: The function called per iteration.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Object)*: Returns `object`.
#### Example
```js
_.forOwn({ '0': 'zero', '1': 'one', 'length': 2 }, function(num, key) {
console.log(key);
});
// => logs '0', '1', and 'length' (property order is not guaranteed across environments)
```
* * *
### `_.forOwnRight(object, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2479 "View in source") [Ⓣ][1]
This method is like `_.forOwn` except that it iterates over elements
of a `collection` in the opposite order.
#### Arguments
1. `object` *(Object)*: The object to iterate over.
2. `[callback=identity]` *(Function)*: The function called per iteration.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Object)*: Returns `object`.
#### Example
```js
_.forOwnRight({ '0': 'zero', '1': 'one', 'length': 2 }, function(num, key) {
console.log(key);
});
// => logs 'length', '1', and '0' assuming `_.forOwn` logs '0', '1', and 'length'
```
* * *
### `_.functions(object)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2508 "View in source") [Ⓣ][1]
Creates a sorted array of property names of all enumerable properties,
own and inherited, of `object` that have function values.
#### Aliases
*_.methods*
#### Arguments
1. `object` *(Object)*: The object to inspect.
#### Returns
*(Array)*: Returns an array of property names that have function values.
#### Example
```js
_.functions(_);
// => ['all', 'any', 'bind', 'bindAll', 'clone', 'compact', 'compose', ...]
```
* * *
### `_.has(object, key)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2533 "View in source") [Ⓣ][1]
Checks if the specified property name exists as a direct property of `object`,
instead of an inherited property.
#### Arguments
1. `object` *(Object)*: The object to inspect.
2. `key` *(string)*: The name of the property to check.
#### Returns
*(boolean)*: Returns `true` if key is a direct property, else `false`.
#### Example
```js
_.has({ 'a': 1, 'b': 2, 'c': 3 }, 'b');
// => true
```
* * *
### `_.invert(object)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2550 "View in source") [Ⓣ][1]
Creates an object composed of the inverted keys and values of the given object.
#### Arguments
1. `object` *(Object)*: The object to invert.
#### Returns
*(Object)*: Returns the created inverted object.
#### Example
```js
_.invert({ 'first': 'fred', 'second': 'barney' });
// => { 'fred': 'first', 'barney': 'second' }
```
* * *
### `_.isArguments(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L1910 "View in source") [Ⓣ][1]
Checks if `value` is an `arguments` object.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is an `arguments` object, else `false`.
#### Example
```js
(function() { return _.isArguments(arguments); })(1, 2, 3);
// => true
_.isArguments([1, 2, 3]);
// => false
```
* * *
### `_.isArray(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L1939 "View in source") [Ⓣ][1]
Checks if `value` is an array.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is an array, else `false`.
#### Example
```js
(function() { return _.isArray(arguments); })();
// => false
_.isArray([1, 2, 3]);
// => true
```
* * *
### `_.isBoolean(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2576 "View in source") [Ⓣ][1]
Checks if `value` is a boolean value.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is a boolean value, else `false`.
#### Example
```js
_.isBoolean(null);
// => false
```
* * *
### `_.isDate(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2594 "View in source") [Ⓣ][1]
Checks if `value` is a date.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is a date, else `false`.
#### Example
```js
_.isDate(new Date);
// => true
```
* * *
### `_.isElement(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2611 "View in source") [Ⓣ][1]
Checks if `value` is a DOM element.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is a DOM element, else `false`.
#### Example
```js
_.isElement(document.body);
// => true
```
* * *
### `_.isEmpty(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2636 "View in source") [Ⓣ][1]
Checks if `value` is empty. Arrays, strings, or `arguments` objects with a
length of `0` and objects with no own enumerable properties are considered
"empty".
#### Arguments
1. `value` *(Array|Object|string)*: The value to inspect.
#### Returns
*(boolean)*: Returns `true` if the `value` is empty, else `false`.
#### Example
```js
_.isEmpty([1, 2, 3]);
// => false
_.isEmpty({});
// => true
_.isEmpty('');
// => true
```
* * *
### `_.isEqual(a, b, [callback], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2693 "View in source") [Ⓣ][1]
Performs a deep comparison between two values to determine if they are
equivalent to each other. If a callback is provided it will be executed
to compare values. If the callback returns `undefined` comparisons will
be handled by the method instead. The callback is bound to `thisArg` and
invoked with two arguments; (a, b).
#### Arguments
1. `a` *(*)*: The value to compare.
2. `b` *(*)*: The other value to compare.
3. `[callback]` *(Function)*: The function to customize comparing values.
4. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(boolean)*: Returns `true` if the values are equivalent, else `false`.
#### Example
```js
var object = { 'name': 'fred' };
var copy = { 'name': 'fred' };
object == copy;
// => false
_.isEqual(object, copy);
// => true
var words = ['hello', 'goodbye'];
var otherWords = ['hi', 'goodbye'];
_.isEqual(words, otherWords, function(a, b) {
var reGreet = /^(?:hello|hi)$/i,
aGreet = _.isString(a) && reGreet.test(a),
bGreet = _.isString(b) && reGreet.test(b);
return (aGreet || bGreet) ? (aGreet == bGreet) : undefined;
});
// => true
```
* * *
### `_.isFinite(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2725 "View in source") [Ⓣ][1]
Checks if `value` is, or can be coerced to, a finite number.
Note: This is not the same as native `isFinite` which will return true for
booleans and empty strings. See http://es5.github.io/#x15.1.2.5.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is finite, else `false`.
#### Example
```js
_.isFinite(-101);
// => true
_.isFinite('10');
// => true
_.isFinite(true);
// => false
_.isFinite('');
// => false
_.isFinite(Infinity);
// => false
```
* * *
### `_.isFunction(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2742 "View in source") [Ⓣ][1]
Checks if `value` is a function.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is a function, else `false`.
#### Example
```js
_.isFunction(_);
// => true
```
* * *
### `_.isNaN(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2805 "View in source") [Ⓣ][1]
Checks if `value` is `NaN`.
Note: This is not the same as native `isNaN` which will return `true` for
`undefined` and other non-numeric values. See http://es5.github.io/#x15.1.2.4.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is `NaN`, else `false`.
#### Example
```js
_.isNaN(NaN);
// => true
_.isNaN(new Number(NaN));
// => true
isNaN(undefined);
// => true
_.isNaN(undefined);
// => false
```
* * *
### `_.isNull(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2827 "View in source") [Ⓣ][1]
Checks if `value` is `null`.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is `null`, else `false`.
#### Example
```js
_.isNull(null);
// => true
_.isNull(undefined);
// => false
```
* * *
### `_.isNumber(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2846 "View in source") [Ⓣ][1]
Checks if `value` is a number.
Note: `NaN` is considered a number. See http://es5.github.io/#x8.5.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is a number, else `false`.
#### Example
```js
_.isNumber(8.4 * 5);
// => true
```
* * *
### `_.isObject(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2772 "View in source") [Ⓣ][1]
Checks if `value` is the language type of Object.
(e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is an object, else `false`.
#### Example
```js
_.isObject({});
// => true
_.isObject([1, 2, 3]);
// => true
_.isObject(1);
// => false
```
* * *
### `_.isPlainObject(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2875 "View in source") [Ⓣ][1]
Checks if `value` is an object created by the `Object` constructor.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if `value` is a plain object, else `false`.
#### Example
```js
function Shape() {
this.x = 0;
this.y = 0;
}
_.isPlainObject(new Shape);
// => false
_.isPlainObject([1, 2, 3]);
// => false
_.isPlainObject({ 'x': 0, 'y': 0 });
// => true
```
* * *
### `_.isRegExp(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2900 "View in source") [Ⓣ][1]
Checks if `value` is a regular expression.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is a regular expression, else `false`.
#### Example
```js
_.isRegExp(/fred/);
// => true
```
* * *
### `_.isString(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2917 "View in source") [Ⓣ][1]
Checks if `value` is a string.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is a string, else `false`.
#### Example
```js
_.isString('fred');
// => true
```
* * *
### `_.isUndefined(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2935 "View in source") [Ⓣ][1]
Checks if `value` is `undefined`.
#### Arguments
1. `value` *(*)*: The value to check.
#### Returns
*(boolean)*: Returns `true` if the `value` is `undefined`, else `false`.
#### Example
```js
_.isUndefined(void 0);
// => true
```
* * *
### `_.keys(object)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L1973 "View in source") [Ⓣ][1]
Creates an array composed of the own enumerable property names of an object.
#### Arguments
1. `object` *(Object)*: The object to inspect.
#### Returns
*(Array)*: Returns an array of property names.
#### Example
```js
_.keys({ 'one': 1, 'two': 2, 'three': 3 });
// => ['one', 'two', 'three'] (property order is not guaranteed across environments)
```
* * *
### `_.mapValues(object, [callback=identity], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L2975 "View in source") [Ⓣ][1]
Creates an object with the same keys as `object` and values generated by
running each own enumerable property of `object` through the callback.
The callback is bound to `thisArg` and invoked with three arguments;
(value, key, object).
If a property name is provided for `callback` the created "_.pluck" style
callback will return the property value of the given element.
If an object is provided for `callback` the created "_.where" style callback
will return `true` for elements that have the properties of the given object,
else `false`.
#### Arguments
1. `object` *(Object)*: The object to iterate over.
2. `[callback=identity]` *(Function|Object|string)*: The function called per iteration. If a property name or object is provided it will be used to create a "_.pluck" or "_.where" style callback, respectively.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Array)*: Returns a new object with values of the results of each `callback` execution.
#### Example
```js
_.mapValues({ 'a': 1, 'b': 2, 'c': 3} , function(num) { return num * 3; });
// => { 'a': 3, 'b': 6, 'c': 9 }
var characters = {
'fred': { 'name': 'fred', 'age': 40 },
'pebbles': { 'name': 'pebbles', 'age': 1 }
};
// using "_.pluck" callback shorthand
_.mapValues(characters, 'age');
// => { 'fred': 40, 'pebbles': 1 }
```
* * *
### `_.merge(object, [source], [callback], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3036 "View in source") [Ⓣ][1]
Recursively merges own enumerable properties of the source object(s), that
don't resolve to `undefined` into the destination object. Subsequent sources
will overwrite property assignments of previous sources. If a callback is
provided it will be executed to produce the merged values of the destination
and source properties. If the callback returns `undefined` merging will
be handled by the method instead. The callback is bound to `thisArg` and
invoked with two arguments; (objectValue, sourceValue).
#### Arguments
1. `object` *(Object)*: The destination object.
2. `[source]` *(...Object)*: The source objects.
3. `[callback]` *(Function)*: The function to customize merging properties.
4. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Object)*: Returns the destination object.
#### Example
```js
var names = {
'characters': [
{ 'name': 'barney' },
{ 'name': 'fred' }
]
};
var ages = {
'characters': [
{ 'age': 36 },
{ 'age': 40 }
]
};
_.merge(names, ages);
// => { 'characters': [{ 'name': 'barney', 'age': 36 }, { 'name': 'fred', 'age': 40 }] }
var food = {
'fruits': ['apple'],
'vegetables': ['beet']
};
var otherFood = {
'fruits': ['banana'],
'vegetables': ['carrot']
};
_.merge(food, otherFood, function(a, b) {
return _.isArray(a) ? a.concat(b) : undefined;
});
// => { 'fruits': ['apple', 'banana'], 'vegetables': ['beet', 'carrot] }
```
* * *
### `_.omit(object, [callback], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3092 "View in source") [Ⓣ][1]
Creates a shallow clone of `object` excluding the specified properties.
Property names may be specified as individual arguments or as arrays of
property names. If a callback is provided it will be executed for each
property of `object` omitting the properties the callback returns truey
for. The callback is bound to `thisArg` and invoked with three arguments;
(value, key, object).
#### Arguments
1. `object` *(Object)*: The source object.
2. `[callback]` *(Function|...string|string[])*: The properties to omit or the function called per iteration.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Object)*: Returns an object without the omitted properties.
#### Example
```js
_.omit({ 'name': 'fred', 'age': 40 }, 'age');
// => { 'name': 'fred' }
_.omit({ 'name': 'fred', 'age': 40 }, function(value) {
return typeof value == 'number';
});
// => { 'name': 'fred' }
```
* * *
### `_.pairs(object)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3133 "View in source") [Ⓣ][1]
Creates a two dimensional array of an object's key-value pairs,
i.e. `[[key1, value1], [key2, value2]]`.
#### Arguments
1. `object` *(Object)*: The object to inspect.
#### Returns
*(Array)*: Returns new array of key-value pairs.
#### Example
```js
_.pairs({ 'barney': 36, 'fred': 40 });
// => [['barney', 36], ['fred', 40]] (property order is not guaranteed across environments)
```
* * *
### `_.pick(object, [callback], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3173 "View in source") [Ⓣ][1]
Creates a shallow clone of `object` composed of the specified properties.
Property names may be specified as individual arguments or as arrays of
property names. If a callback is provided it will be executed for each
property of `object` picking the properties the callback returns truey
for. The callback is bound to `thisArg` and invoked with three arguments;
(value, key, object).
#### Arguments
1. `object` *(Object)*: The source object.
2. `[callback]` *(Function|...string|string[])*: The function called per iteration or property names to pick, specified as individual property names or arrays of property names.
3. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(Object)*: Returns an object composed of the picked properties.
#### Example
```js
_.pick({ 'name': 'fred', '_userid': 'fred1' }, 'name');
// => { 'name': 'fred' }
_.pick({ 'name': 'fred', '_userid': 'fred1' }, function(value, key) {
return key.charAt(0) != '_';
});
// => { 'name': 'fred' }
```
* * *
### `_.transform(object, [callback=identity], [accumulator], [thisArg])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3228 "View in source") [Ⓣ][1]
An alternative to `_.reduce` this method transforms `object` to a new
`accumulator` object which is the result of running each of its own
enumerable properties through a callback, with each callback execution
potentially mutating the `accumulator` object. The callback is bound to
`thisArg` and invoked with four arguments; (accumulator, value, key, object).
Callbacks may exit iteration early by explicitly returning `false`.
#### Arguments
1. `object` *(Array|Object)*: The object to iterate over.
2. `[callback=identity]` *(Function)*: The function called per iteration.
3. `[accumulator]` *(*)*: The custom accumulator value.
4. `[thisArg]` *(*)*: The `this` binding of `callback`.
#### Returns
*(*)*: Returns the accumulated value.
#### Example
```js
var squares = _.transform([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], function(result, num) {
num *= num;
if (num % 2) {
return result.push(num) < 3;
}
});
// => [1, 9, 25]
var mapped = _.transform({ 'a': 1, 'b': 2, 'c': 3 }, function(result, num, key) {
result[key] = num * 3;
});
// => { 'a': 3, 'b': 6, 'c': 9 }
```
* * *
### `_.values(object)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L3262 "View in source") [Ⓣ][1]
Creates an array composed of the own enumerable property values of `object`.
#### Arguments
1. `object` *(Object)*: The object to inspect.
#### Returns
*(Array)*: Returns an array of property values.
#### Example
```js
_.values({ 'one': 1, 'two': 2, 'three': 3 });
// => [1, 2, 3] (property order is not guaranteed across environments)
```
* * *
## `“Utilities” Methods`
### `_.constant(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6126 "View in source") [Ⓣ][1]
Creates a function that returns `value`.
#### Arguments
1. `value` *(*)*: The value to return from the new function.
#### Returns
*(Function)*: Returns the new function.
#### Example
```js
var object = { 'name': 'fred' };
var getter = _.constant(object);
getter() === object;
// => true
```
* * *
### `_.createCallback([func=identity], [thisArg], [argCount])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6163 "View in source") [Ⓣ][1]
Produces a callback bound to an optional `thisArg`. If `func` is a property
name the created callback will return the property value for a given element.
If `func` is an object the created callback will return `true` for elements
that contain the equivalent object properties, otherwise it will return `false`.
#### Arguments
1. `[func=identity]` *(*)*: The value to convert to a callback.
2. `[thisArg]` *(*)*: The `this` binding of the created callback.
3. `[argCount]` *(number)*: The number of arguments the callback accepts.
#### Returns
*(Function)*: Returns a callback function.
#### Example
```js
var characters = [
{ 'name': 'barney', 'age': 36 },
{ 'name': 'fred', 'age': 40 }
];
// wrap to create custom callback shorthands
_.createCallback = _.wrap(_.createCallback, function(func, callback, thisArg) {
var match = /^(.+?)__([gl]t)(.+)$/.exec(callback);
return !match ? func(callback, thisArg) : function(object) {
return match[2] == 'gt' ? object[match[1]] > match[3] : object[match[1]] < match[3];
};
});
_.filter(characters, 'age__gt38');
// => [{ 'name': 'fred', 'age': 40 }]
```
* * *
### `_.escape(string)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6212 "View in source") [Ⓣ][1]
Converts the characters `&`, `<`, `>`, `"`, and `'` in `string` to their
corresponding HTML entities.
#### Arguments
1. `string` *(string)*: The string to escape.
#### Returns
*(string)*: Returns the escaped string.
#### Example
```js
_.escape('Fred, Wilma, & Pebbles');
// => 'Fred, Wilma, & Pebbles'
```
* * *
### `_.identity(value)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6230 "View in source") [Ⓣ][1]
This method returns the first argument provided to it.
#### Arguments
1. `value` *(*)*: Any value.
#### Returns
*(*)*: Returns `value`.
#### Example
```js
var object = { 'name': 'fred' };
_.identity(object) === object;
// => true
```
* * *
### `_.mixin([object=lodash], source, [options])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6262 "View in source") [Ⓣ][1]
Adds function properties of a source object to the destination object.
If `object` is a function methods will be added to its prototype as well.
#### Arguments
1. `[object=lodash]` *(Function|Object)*: object The destination object.
2. `source` *(Object)*: The object of functions to add.
3. `[options]` *(Object)*: The options object.
4. `[options.chain=true]` *(boolean)*: Specify whether the functions added are chainable.
#### Example
```js
function capitalize(string) {
return string.charAt(0).toUpperCase() + string.slice(1).toLowerCase();
}
_.mixin({ 'capitalize': capitalize });
_.capitalize('fred');
// => 'Fred'
_('fred').capitalize().value();
// => 'Fred'
_.mixin({ 'capitalize': capitalize }, { 'chain': false });
_('fred').capitalize();
// => 'Fred'
```
* * *
### `_.noConflict()`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6318 "View in source") [Ⓣ][1]
Reverts the '_' variable to its previous value and returns a reference to
the `lodash` function.
#### Returns
*(Function)*: Returns the `lodash` function.
#### Example
```js
var lodash = _.noConflict();
```
* * *
### `_.noop()`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6335 "View in source") [Ⓣ][1]
A no-operation function.
#### Example
```js
var object = { 'name': 'fred' };
_.noop(object) === undefined;
// => true
```
* * *
### `_.now`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6352 "View in source") [Ⓣ][1]
Gets the number of milliseconds that have elapsed since the Unix epoch
(1 January 1970 00:00:00 UTC).
#### Example
```js
var stamp = _.now();
_.defer(function() { console.log(_.now() - stamp); });
// => logs the number of milliseconds it took for the deferred function to be called
```
* * *
### `_.parseInt(value, [radix])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6375 "View in source") [Ⓣ][1]
Converts the given value into an integer of the specified radix.
If `radix` is `undefined` or `0` a `radix` of `10` is used unless the
`value` is a hexadecimal, in which case a `radix` of `16` is used.
Note: This method avoids differences in native ES3 and ES5 `parseInt`
implementations. See http://es5.github.io/#E.
#### Arguments
1. `value` *(string)*: The value to parse.
2. `[radix]` *(number)*: The radix used to interpret the value to parse.
#### Returns
*(number)*: Returns the new integer value.
#### Example
```js
_.parseInt('08');
// => 8
```
* * *
### `_.property(key)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6404 "View in source") [Ⓣ][1]
Creates a "_.pluck" style function, which returns the `key` value of a
given object.
#### Arguments
1. `key` *(string)*: The name of the property to retrieve.
#### Returns
*(Function)*: Returns the new function.
#### Example
```js
var characters = [
{ 'name': 'fred', 'age': 40 },
{ 'name': 'barney', 'age': 36 }
];
var getName = _.property('name');
_.map(characters, getName);
// => ['barney', 'fred']
_.sortBy(characters, getName);
// => [{ 'name': 'barney', 'age': 36 }, { 'name': 'fred', 'age': 40 }]
```
* * *
### `_.random([min=0], [max=1], [floating=false])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6437 "View in source") [Ⓣ][1]
Produces a random number between `min` and `max` (inclusive). If only one
argument is provided a number between `0` and the given number will be
returned. If `floating` is truey or either `min` or `max` are floats a
floating-point number will be returned instead of an integer.
#### Arguments
1. `[min=0]` *(number)*: The minimum possible value.
2. `[max=1]` *(number)*: The maximum possible value.
3. `[floating=false]` *(boolean)*: Specify returning a floating-point number.
#### Returns
*(number)*: Returns a random number.
#### Example
```js
_.random(0, 5);
// => an integer between 0 and 5
_.random(5);
// => also an integer between 0 and 5
_.random(5, true);
// => a floating-point number between 0 and 5
_.random(1.2, 5.2);
// => a floating-point number between 1.2 and 5.2
```
* * *
### `_.result(object, key)`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6495 "View in source") [Ⓣ][1]
Resolves the value of property `key` on `object`. If `key` is a function
it will be invoked with the `this` binding of `object` and its result returned,
else the property value is returned. If `object` is falsey then `undefined`
is returned.
#### Arguments
1. `object` *(Object)*: The object to inspect.
2. `key` *(string)*: The name of the property to resolve.
#### Returns
*(*)*: Returns the resolved value.
#### Example
```js
var object = {
'cheese': 'crumpets',
'stuff': function() {
return 'nonsense';
}
};
_.result(object, 'cheese');
// => 'crumpets'
_.result(object, 'stuff');
// => 'nonsense'
```
* * *
### `_.runInContext([context=root])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L469 "View in source") [Ⓣ][1]
Create a new `lodash` function using the given context object.
#### Arguments
1. `[context=root]` *(Object)*: The context object.
#### Returns
*(Function)*: Returns the `lodash` function.
* * *
### `_.template(text, data, [options], [sourceURL], [variable])`
# [Ⓢ](https://github.com/lodash/lodash/blob/2.4.2/lodash.js#L6588 "View in source") [Ⓣ][1]
A micro-templating method that handles arbitrary delimiters, preserves
whitespace, and correctly escapes quotes within interpolated code.
Note: In the development build, `_.template` utilizes sourceURLs for easier
debugging. See http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl
For more information on precompiling templates see:
https://lodash.com/custom-builds
For more information on Chrome extension sandboxes see:
http://developer.chrome.com/stable/extensions/sandboxingEval.html
#### Arguments
1. `text` *(string)*: The template text.
2. `data` *(Object)*: The data object used to populate the text.
3. `[options]` *(Object)*: The options object.
4. `[options.escape]` *(RegExp)*: The "escape" delimiter.
5. `[options.evaluate]` *(RegExp)*: The "evaluate" delimiter.
6. `[options.imports]` *(Object)*: An object to import into the template as local variables.
7. `[options.interpolate]` *(RegExp)*: The "interpolate" delimiter.
8. `[sourceURL]` *(string)*: The sourceURL of the template's compiled source.
9. `[variable]` *(string)*: The data object variable name.
#### Returns
*(Function|string)*: Returns a compiled function when no `data` object
is given, else it returns the interpolated text.
#### Example
```js
// using the "interpolate" delimiter to create a compiled template
var compiled = _.template('hello <%= name %>');
compiled({ 'name': 'fred' });
// => 'hello fred'
// using the "escape" delimiter to escape HTML in data property values
_.template('<%- value %>', { 'value': '